diff --git a/Library/Homebrew/extend/os/mac/keg.rb b/Library/Homebrew/extend/os/mac/keg.rb
index 0c4a0eeb61..e681709b7d 100644
--- a/Library/Homebrew/extend/os/mac/keg.rb
+++ b/Library/Homebrew/extend/os/mac/keg.rb
@@ -192,7 +192,7 @@ module OS
       # reproducible bottles.
       def consistent_reproducible_symlink_permissions!
         path.find do |file|
-          File.lchmod 0777, file if file.symlink?
+          file.lchmod 0777 if file.symlink?
         end
       end
     end
diff --git a/Library/Homebrew/install.rb b/Library/Homebrew/install.rb
index da11838062..99256ae791 100644
--- a/Library/Homebrew/install.rb
+++ b/Library/Homebrew/install.rb
@@ -1,4 +1,4 @@
-# typed: true # rubocop:todo Sorbet/StrictSigil
+# typed: strict
 # frozen_string_literal: true
 
 require "diagnostic"
@@ -17,7 +17,7 @@ module Homebrew
     class << self
       sig { params(all_fatal: T::Boolean).void }
       def perform_preinstall_checks_once(all_fatal: false)
-        @perform_preinstall_checks_once ||= {}
+        @perform_preinstall_checks_once ||= T.let({}, T.nilable(T::Hash[T::Boolean, TrueClass]))
         @perform_preinstall_checks_once[all_fatal] ||= begin
           perform_preinstall_checks(all_fatal:)
           true
@@ -28,7 +28,7 @@ module Homebrew
       def check_cc_argv(cc)
         return unless cc
 
-        @checks ||= Diagnostic::Checks.new
+        @checks ||= T.let(Diagnostic::Checks.new, T.nilable(Homebrew::Diagnostic::Checks))
         opoo <<~EOS
           You passed `--cc=#{cc}`.
 
@@ -422,8 +422,14 @@ module Homebrew
         end
       end
 
-      sig { params(formula: Formula, dependencies: T::Array[[Dependency, Options]]).void }
-      def print_dry_run_dependencies(formula, dependencies)
+      sig {
+        params(
+          formula:      Formula,
+          dependencies: T::Array[[Dependency, Options]],
+          _block:       T.proc.params(arg0: Formula).void,
+        ).void
+      }
+      def print_dry_run_dependencies(formula, dependencies, &_block)
         return if dependencies.empty?
 
         ohai "Would install #{Utils.pluralize("dependency", dependencies.count, include_count: true)} " \
diff --git a/Library/Homebrew/keg.rb b/Library/Homebrew/keg.rb
index d38a7b92d2..45ce093945 100644
--- a/Library/Homebrew/keg.rb
+++ b/Library/Homebrew/keg.rb
@@ -164,7 +164,11 @@ class Keg
   ).sort.uniq.freeze
   end
 
-  attr_reader :path, :name, :linked_keg_record, :opt_record
+  sig { returns(String) }
+  attr_reader :name
+
+  sig { returns(Pathname) }
+  attr_reader :path, :linked_keg_record, :opt_record
 
   protected :path
 
@@ -188,6 +192,7 @@ class Keg
     @require_relocation = false
   end
 
+  sig { returns(Pathname) }
   def rack
     path.parent
   end
diff --git a/Library/Homebrew/keg_relocate.rb b/Library/Homebrew/keg_relocate.rb
index 0996d62bc4..35449f5d18 100644
--- a/Library/Homebrew/keg_relocate.rb
+++ b/Library/Homebrew/keg_relocate.rb
@@ -212,6 +212,7 @@ class Keg
 
     changed_files = T.let([], T::Array[Pathname])
     files.map { path.join(_1) }.group_by { |f| f.stat.ino }.each_value do |first, *rest|
+      first = T.must(first)
       s = first.open("rb", &:read)
 
       # Use full prefix replacement for Homebrew-created files when using selective relocation